The Server Rack FAQ » 4 Post Racks

How tall can a server rack be?

jwood — Tue, 05 Jul 2011 17:46:33 +0000

55U, Open Frame Rack

Server racks come in many different sizes. Some are as short as a 4U Desktop Rack and might only be 9″ tall. Others found in data centers may be as tall as 8 or 9 feet and allow for as much as 55U of equipment space. In many data center environments, rack space becomes important, as the need to rack more equipment such as servers, storage devices, network switches and PDUs is part of the daily challenge. In many instances, limited square footage can present a problem. So what do you do when you run out of floor space for additional server racks? You could go vertical. Why not consider replacing traditional size, server racks with taller server racks that accommodate more equipment without the need for additional floor space? The most common rack heights found in data centers are typically around the 42U to 44U range. By the way, one “U” or “RU” space is 1.75″ tall. So, by replacing a 42U with a 55U, you gain 13U (22.75″), or 30% more rack space. In cases where hundreds of racks or more are in use, that translates into lots of extra equipment space.

50U Open Frame Racks may be bayed together with two, 55U Racks, for example. All four server racks may be equipped with top Air dams, and the rack on each end also may have a side Air Dam installed. Air Dams act like an eave on top of the rack, sticking out 5″ – 10″. The side dams also protrude out 5″ – 10″. Air Dams are used in tandem with floor grates to improve air containment. These racks may also have optional, side panels for enclosing the two ends of the bay of racks.

On the flip side

The front of a server rack loaded with equipment looks cool, but the back of the rack is where things can get a little hairy, and organization is key to keeping your sanity. That’s why it’s important that a rack have vertical cable bar options, a place to mount vertical PDUs and in some cases, LAN and Power assemblies for network switch ports, etc.

See Open Frame, 55U Racks for sale.

Network switches, patch panels, servers

Open Frame Equipment Racks

jwood — Tue, 16 Nov 2010 22:19:45 +0000

Open frame server racks function very similar to Rack Enclosures but without doors or side panels. The benefits of open frame, equipment racks are largely economical. The cost is typically less than half that of a fully enclosed rackmount cabinet.

The main benefits of open frame racks are:

low cost
easy access to cabling
unrestricted airflow optimizes cooling
ease of installation
shipping costs are less

The main disadvantages to open frame racks are:

lack of security
cosmetic – enclosed racks have a cleaner look

Open frame racks can be coupled together with a simple, inexpensive, baying kit, making them ideal for data centers. The cable management on an open frame, equipment rack is very simple. A vertical, cable management bar is typically included and provides an innovative and simple means of routing any type of cables.

Open frame racks typically have a fixed mounting depth. The most common depth is 29″ which is compatible with modern equipment from all OEMs. The equipment racks usually have square mounting holes and use cage nuts.

Open frame racks come in several sizes:

Most recently, a 55U open frame rack has become available.

Here’s an example of what the rear of an open frame rack, filled with servers and equipment, might look like.
This one is shown coupled together with a second open frame rack.

Here’s a great example of three open frame racks bayed together in a server room.

Links to More Information:

Dell Static Rails

will — Mon, 24 May 2010 21:15:02 +0000

Some of the Dell 11g servers have a static rail available for installations where the standard Ready Rails are incompatible or for use in 2Post installations. This Dell rail kit is configurable depending upon what type of rack is used. Section A of the rail kit is an assembly that has the new Ready Rail mounting pins for use in square hole racks as well as a set of clearance holes for use in any type of rack. This mechanism is similar to the previous generation of Dell Rail Kits in that the mechanism rotates to allow for the use of both types of attachment methods. The difference in this mechanism is that it must be unscrewed compared to the previous generation rail kit that used a locking lever. The previous generation rail kit also had PEM nuts instead of clearance holes. Section B is the primary support bracket for 2Post centermount applications. This support bracket is riveted directly to the main rail frame and uses clearance holes as the attachment method. Section C is an adjustable bracket with a range of: 3″ to 6″. This bracket is used for 2Post flushmount configurations. These brackets can be removed if the front assembly is removed first, however they cannot be reversed. These brackets have clearance holes for use in any type of mounting interface. Section D is a 13 7/16″ bracket that is similar to Section A having both the Ready Rail mounting pins on one end and clearance holes on the other end. This bracket is reversable to allow the use of both attachment methods. In 2Post centermount installations the clearance holes are used in conjunction with section B. This allows the rail to be installed in 2Post racks with center channels ranging in size from: 3″ to 10 1/16″. In 4Post installations this bracket is configured based on the mounting interface. The Ready Rail mounting pins are used in square hole racks, the clearance holes are used for any type of rack. In 4Post installations this bracket allows the rail to to be installed in a range of: 23″ to 32 9/16″ using the Ready Rail mounting pins and 23 1/4″ to 33 5/16″ using the clearance holes.

The Dell static rail is susceptible to obstructions in 4Post racks in all 4 sections shown in the photo. 4Post racks with mounting post that are not a simple “L” shape will have the highest potential of causing an obstruction with Section A. If an obstruction occurs with Section C then the bracket can simply be removed. Obstructions caused by Section B will be difficult to resolve due to the permanent attachment of the support bracket. Obstructions in this area will more than likely effect Section D as well and will be equally difficult to resolve. In situations where unresolvable obstructions are preventing the proper installation of this rail kit the recommended solution is to use a 3rd Party Rail kit, P/N: 1UBRK-R4. This rail kit is far less likely to have the obstruction issues that the Dell Rail kit is vulnerable to.

Open Frame Racks

will — Wed, 19 May 2010 20:18:20 +0000

RackSolutions utilizes open frame racks for its own internal use. In fact, they happen to be the racks RackSolutions designs and manufactures at its facility, P/N: RACK-111. In the photo you can see we have a pair of flushmount monitors, P/N: 7U-RACKMON. These flushmount monitors provide a very clean professional look and are compatible with the Dell E176FP flat panel monitor. Below the monitor on the left is a rackmount drawer, P/N: 4UDRAWER-162. If there is one product that will be indispensable in a rack, the rackmount drawers are it. Under each monitor, there is a small slide out keyboard, P/N: 1UKBY-126. These are very economical keyboards with a handy storage bin behind the keyboard itself. Notice the large, tool-less filler panels in the center rack, P/N: FILLER-PANEL-8U-DC. If there is one thing that can be done to prevent cooling issues, even in an open frame rack, it’s using filler panels to eliminate the mixing of hot and cold air. On the far right of the photo is a Vertical Cable Organizer. This cable management bar comes standard on the rack and can be mounted on the front or rear, wherever cables need to be managed.

The rack on the far right has all the networking equipment as well as the phone system. Using a 4Post rack works ok for this type of equipment, but the large amount of cabling can be managed more efficiently using a 2post rack, P/N: RELAY-RACK. A product that is not as apparent in the photo but is another indispensable piece of equipment are the sliding shelves, P/N: 1USHL-115. The 115 line of shelves was designed for larger pieces of equipment. However, in our racks we use it for the smaller, peripheral equipment. Notice in the top of the rack on the right. There are numerous, small, peripheral types of equipment all mounted on a sliding shelf. There is also a sliding shelf installed in the center rack that is used just as a pull-out work space.

Another product that is used extensively in our racks but not very apparent in this photo is the tool-less fixed rail, P/N: 2UKIT-109-QR. These rails take longer to get out of the box than they do to install in the rack. They will mount any type of rackmount server. These rails allow the server to be quickly installed or removed from the rack. They are not slide rails. Therefore, the server must be supported when removing the rails from the rack. There are numerous advantages to using this type of rail; it will mount your legacy servers that don’t have rails. It will mount your current servers without your having to purchase the expensive OEM rails. It will mount the next servers that you upgrade to without your having to ever buy another set of rails. If you consider that OEM rails can cost upwards of $250-$300 a set and in this small 3 rack installation there are 17 pieces of equipment that require rail kits, the cost savings just for rails could be over $4,000 for a single hardware refresh. If this cost savings is projected over several generations of servers, the economics of using a generic type of mounting system is significant.

Shown below are 3 Open Frame Racks bayed together.

See Open Frame Racks for sale.

Rackmount Drawers and Boxes

will — Wed, 19 May 2010 16:03:04 +0000

Why would you want to put drawers or boxes in your server rack? Like most IT Staff there is a ton of stuff that usually gets left sitting on top of the equipment. Software, manuals, test equipment, the list is endless. What rack drawers and boxes allow you to do is secure all this stuff where it is used the most, next to the equipment.

Rack drawers and boxes are available in several sizes and configurations. The drawers and boxes are 14 1/4″ in depth. This allows them to be mounted back to back in a 29″ deep rack. This maximizes the usable space and provides the versatility to choose what option works best for a given installation. The drawers and the boxes with lids are lockable to secure expensive equipment such as laptops or test equipment in the rack.

Rack drawers and boxes will make a difference to reduce the clutter and increase the organization in your rack. The photo shows the internal racks here at RackSolutions and you can see that we “Eat our own dog food” utilizing drawers on the front and rear of our racks.

Order Rackmount Drawers and Boxes

Mounting Cisco UCS Slide Rails in a Threaded Hole Rack

will — Tue, 18 May 2010 22:06:07 +0000

The slide rail kits for the Cisco UCS equipment are not compatible with threaded hole racks. However, if you are in a situation where you have to use this type of rack, there is a solution. The solution is RackSolution’s Adapter Brackets. These brackets will convert threaded hole racks to square hole racks allowing the use of the standard Cisco Slide Rails. The adapter brackets also allow for the adjustment of the rack if the installation depth is outside of the range of the Cisco Slide Rails. The minimum installation depth of the Cisco Slide Rails is 26 5/8″. If for example your rack has an installation depth of 24″ then the Cisco Slide Rails are not going to fit into your rack. By adding 2″ adapter brackets to the front and rear of your rack you will increase the installation depth from 24″ to 28″ which is well within the installation depth range of the Cisco Slide Rails. The adapter brackets that work with the Cisco Slide Rails are available in an assortment of sizes ranging from 2″ to 3 1/2″.

Rack Compatibility	Any threaded hole rack
Rail Extension	28 1/4″
Overall Installation Depth	36″ with CMA 34 5/8″ no CMA
Minimum Installation Depth	22 7/8″
Maximum Installation Depth	33 15/16″
Order Adapater Brackets P/N: 1UBRK-200 Cisco UCS C200, C210, C250 Rail Overview

Cisco’s Slide Rail Kit for UCS C200, C210, & C250

will — Mon, 17 May 2010 20:41:23 +0000

Cisco’s line of Unified Computing Systems (UCS) are available with a tool-less slide rail. This rail kit is compatible with two different types of tool-less mounting interfaces: 3/8″ Square Hole and 1/4″ Round Hole racks. The mechanism on this rail kit has a spring loaded sleeve that retracts for round hole racks. For installations that use square hole racks, the sleeve stays in place and centers the mounting pins in the square holes. The mechanism wraps around the outside of the rack uprights and has a small latch to secure the mechanism in place.

Rack Compatibility	3/8″ Square Hole Racks 1/4″ Round Hole Racks
Rail Extension	28 1/4″
Overall Installation Depth	36″ with CMA 34 5/8″ no CMA
Installation Depth Range	min: 26 5/8″ max: 37 15/16″

Installing UCS Rails in a Threaded Hole Rack Installing UCS Rails in a 2Post Rack

Dell’s Ready Rail for 11G Servers

will — Wed, 15 Apr 2009 18:28:33 +0000

Dell has introduced a new design for their 11G Servers. This rail kit is like no other before. The first thing that you will notice is that the rails themselves no longer attach to the rear mounting surface of the rack post but now wrap around and attach to the front mounting surface. The square hooks that Dell has used for years on their rail kits have been replaced by a set of pins and a small safety latch. The mounting depth range of this new rail kit changed from the previous kit as well. The following table compares the previous rail kit with the new one.

	Mounting Depth	Overal Depth
Universal Rail	26 15/16″ to 29 5/16″	35 3/16″
Ready Rail	27 1/4″ to 29 3/4″	35 3/8″

The 11G Rail Kit is less likely to cause obstructions than the Universal Rail kit. The 11G Rail Kit has a very clean line from the front to the rear rack post. There are very few racks that this rail kit won’t install in. The exception being a rack that has threaded holes instead of the common square holes. If your rack is tapped then this rail kit will not work! The only option for installations that use a rack with tapped holes is to use a fixed rail or a 3rd Party Rail Kit.

The installations that use 2PostRelay Racks will be able to use the Ready Rail with the addition of a 2Post Conversion Kit. The 2Post Conversion Kits are a set of 4 steel brackets that when installed onto a 2Post Rack provide the 4 corner attachments similar to a standard Server Rack. These Conversion Kits are available in sizes from 2-7 Rack Units and are capable of mounting multiple servers.

Flushmount an LCD monitor in a rack

will — Mon, 08 Dec 2008 18:45:29 +0000

There are several options available for installing a Flatscreen Display into a Server Rack. The simplest and most economical method is to use a Flushmount Bracket. This product will allow Flatscreens as large as 20″ to be installed into a Server Rack.

The higher end products provide a more integrated look to the installation. These products provide a faceplate that covers the front of the flatscreen. Products like this are only compatible with a particular model of display and therefore must be used with very specific installations.

Flushmount Bracket

Flushmount Display with Cover

Click on Photos for Additional Information

How to Rackmount a Dell Precision Workstation – T3400, T5400, & T7400

will — Mon, 20 Oct 2008 19:49:39 +0000

The Dell Precision Workstations can be rackmounted using several methods. The T3400 and the T5400 can use a Tower to Rack Conversion Kit. This kit allows the Workstations to be installed into most types of Server Racks. This kit is not compatible with the T7400. Additional installation methods utilize rackmount shelves. In order to choose the proper shelf you first must know the dimensions and weight of the equipment.

Model	Dimensions (W x H x D)	Weight
T3400	6.8″ x 17.6″ x 18.4″	39lbs
T5400	6.73″ x 17.64″ 18.54″	39lbs
T7400	8.5″ x 22.26″ x 22.3″	55lbs

The opening of a Server Rack is 17.7″ wide. The Dell Precision T3400 and the T5400 can both lay on their side however the Dell Precision T7400 would be too wide to lay on it’s side. The T7400 can be installed in pairs on a shelf if it’s standing up.

There are two types of Shelves that can be used to install the Dell Precision Workstations. The first type is a Fixed Shelf that will support up to 150lbs of equipment. This shelf is an economical and versatile product that will install into any type of Server Rack.

The second type is a Sliding Shelf. These shelves are purchased based on the weight they need to support. The Dell Precision T3400 & the T5400 are both 39lbs which is within the weight limit of any of the Sliding Shelves. The 45lb Capacity Sliding Shelf is the best choice for these workstations. The Dell Precision T7400 has a large chassis and would require a 95lb Capacity Sliding Shelf. The T7400 will have to stand upright on this shelf, however two of them can be installed on this product. The Sliding Shelf has a front and rear equipment stop that secures the equipment. For additional support especially if installing the Precision T7400 in pairs there are nylon straps available that further secure the equipment.